So to start off with, securing Enterprise Applications is probably the area I am weakest in in M365, so forgive me for any mistaken information I present here. I am working on learning and improving in this area, so I want to use this breach as a learning point.
I know it is still very early, the dust hasn't settled completely yet, and new information is still emerging, but I wanted to collect some thoughts while they are still fresh in my head about what I have read. I was not affected by this breach but have been following it closely as a learning exercise.
So this is the kind of breach that has always scared me, through an Enterprise App. They are given a lot of trust, both by us and inside M365. My understanding is our ability to secure these apps is very limited. Actually non-existent unless you purchase Workload ID Premium for every application. It is even unclear if this would have prevented it, as I believe the attack came from legitimate IP addresses, which from my understanding would have likely been allowed under any conditional access policy created.
I am purposely ignoring other controls like not letting users approve applications, because we are talking about applications that would naturally be approved by Admin's, such as this one.
Now from my understanding this breach became widely known on the 16th of October. I am still unclear how it was actually discovered. Obviously this thread was ground zero, but all that was said was that some MSP's identified suspicious activity. How they identified that activity I am unclear, did they have a tool notify them, were they monitoring logs, or did they just happen to stumble upon it?
I am unclear if any tooling actually caught this breach in action. It wasn't until it became known in the above thread that vendors actually started investigating and discovering the compromise, from what I can tell. So while Huntress's response was great, and much better than some, their tooling didn't actually discover or stop this compromise, it was manually initiated once it was reported in this thread.
Now it may seem like I'm picking on Huntress, but I'm not. I'm a current Huntress ITDR subscriber, and they have just been the most vocal, so I'm trying to use them to learn from. I will number each item I would like to see more discussion on:
- One big reasons why they didn't discover it is found in a communication from Huntress in the above thread. They stated:
This activity is an application signing in with a vendor credential, not a user signing in.
Huntress does not currently monitor this type of sign-in, so it did not generate an alert. Our visibility is further limited in tenants without a Microsoft Entra ID P1 or higher license,
So off the hop, this goes back to these Applications being given a lot of trust. I don't know the technical reason's why Huntress doesn't monitor these logins, is it a technical issue on their side, technical issue with M365, or some other reason?
- Another item I am unclear on comes from this thread where it was said:
Separately, we've observed notable new activity: abuse of an additional ConnectWise M365 application (ConnectWise Cloud Management - MS Teams, Application ID 24205314-2b89-4e07-a2a4-579e898a5640) that gave itself Global Administrator
Now, I don't know what permissions the app had initially, but:
A. How can an application give itself Global Administrator? Did someone reconsent to the app's elevated permissions? Or did the app initially get consented to with enough permissions to reassign itself a higher tier of access? But that makes no sense, as I thought only Global Administrators could assign Global Administrators.....
B. This isn't the first mention I've seen of Connectwise applications elevating its permissions, others mentioned seeing this days before the attack became public knowledge. Should these tools not be monitoring for applications upping their Permissions to something more powerful? I would think with the amount of data they can see across all the tenants they monitor, they should be able to identify a trend of ConnectWise apps elevating their permissions somehow across a wide range of tenants. But again, Question A. still stands, how is it able to do that?
- In another spot Huntress mentioned:
and added credentials to multiple applications (including our single-tenant Huntress application unique to this partner's tenant).
Again, I am curious was this activity discovered by the tooling automatically, or was it discovered as a result of the manual investigation? Because I would think having an application add Credentials to other applications, including Huntress's own ITDR application, should raise some red flags inside their tooling.
- Dormant apps suddenly being awakened. There are a lot of reports of people not having used Skykick for a number of years, and it suddenly becoming active again. Yes we should be deleting apps that are no longer being used, but it would be great to have the tooling also at least trigger a notification if suddenly dormant apps are becoming active again.
To me, and again I am no where close to an expert on this stuff, these are the four initial indicators that tooling could use to identify something suspicious is going on, but it seems like nobody caught any of them? I am sure there is a lot I am ignorant about, but I am looking forward to being more educated on the subject. Is there technical reason's why none of the above items were automatically caught in an ITDR system? Or did nobody just see the need?
In Huntress at least, their Application monitoring seems to be more about identifying Rogue applications, rather than actually monitoring those applications activity. Is their application monitoring closer to old school Antivirus Definition Updates, where they just update known bad applications, instead of actively monitoring them? The description on this page makes it sound like that is the case.
Sorry it is so long, but these are the points I've been thinking about through this weekend. Looking forward to hearing others thoughts.